Systemic lupus erythematosus: a blissless disease of too much BLyS (B lymphocyte stimulator) protein.

B lymphocyte stimulator (BLyS) protein is among the novel tumor necrosis factor (TNF) ligands and receptor superfamily members recently described. BLyS protein can promote B cell survival, expansion, and differentiation both and. Constitutive overexpression of BLyS protein can result in systemic lupus erythematosus (SLE)-like disease in mice, and circulating levels of BLyS protein are elevated in a subset of human SLE patients. Treatment of SLE mice with a BLyS protein antagonist ameliorates disease progression and enhances survival. By inference, BLyS protein may also play an important contributory role in pathogenesis and/or propagation of human SLE and becomes a legitimate candidate target for antagonist biologic agents.